Clutch



Nov. 8, 1927.

E. c. 'PFAFF I CLUTCH Filed Jan. 6. 1927 Patented Nov. 8, 1927;

; I wires-star rem ERNESTIC- rteans r ssa-intimate. .1.

CLUTCH. r

App'iication filed January 6, 1 927., Serialjlio. 1 59,27 1.

This invention relates .to a clutch mecha nism designed tov effect a gradual engagement between driving and driven elements by the use of parts which are simple, lllQXPBIlSlVQ,

5 tr adi y. a se b nd i is Pa ticu a ly concerned with 'a means by which'motionis communicated to the driven element through a pair of plates to friction is applied' with equal pressures vfrom oppositesidesof a 1O vi e mbee i :p s nt;imprev m nts.

i t with: the use. of certain I r v i ,,p h t e a ils uch es ea o he a 1 V every point, as well as the nut onlone side and aa ylefc ncer ed. mers sem s n si eh p o ieean imi l sy agement. of. the. l tc rms, t springsbe ng finally compressed SOllCl so as toproduce at all times a flexible engagement,

thereby preventing the transmission of a harsh action to the associated mechanism.

A suggestive embodiment of this invention is set forth in the. cconipanying drawing n the manner following Figure 1 is a fragmentary view in elevation looking toward; one endloflthe clutch ri nme he d shea s a re 't o e the i g m mber i ated the wi on line '2 2 of Fig.1; and.

Fig. 3is an enlarged detail section shoWH versely, related to the wheel axis, which forms the driving member. Mounted upon opposite sides of this flange are frictlon rings 9 which may be made of asbestos or other su-it'a-ble'heat absorbing material, preferably secured tothe ,fiange as by rivets 10. The parts above described constitute a unit which maybe termed the driving member.

The driven 'unit of the present clutch may comprise a hub 11 designed foriastmounting on a shaft (notyshown); Extending radially from the hub isa flange 12 which is disposed by preference adjacent the ring 9 which is proximate to the wheel 5. A circular plate 13 is also associated with .this flange, being dis osed adjacent the other ring 9. Extending tirough aligned openings in the flange and plate are pins or bolts 15,- preferably three in number, and each provided with a stop at one end, as shown. The bolt ends adjacent the wheel are each reduced and threaded to receive a nut 16 the rear end 55 whereof abuts a shoulder which is formed by g- 2 a. ansv se, tio y hrethr us a portion ;ofthe bolt which is ofenlarged'. diameter asv compared toithe' tlir ead-edl jd- 1 1 This bolt portion 17, however, is 'ofless dianfii, eter than the bolt body'sothattheportionll? constitutes, in efiect, an annular recess whereininay be accommodated a compression spring18"haying,by preference, but very few coils which are in parallelism, as shown,

The ends oi the spring are sorelated; t'o the ess-eve re f ien. t e eof. ss t loverlap therew th, whereby the springmay loe com 18 are other compression springs 20, one

surrounding each bolt15, and each tending to, separate the flange and "plate from each otherand from the frict on. rings 9 which theyare designed tog/engage underpressuref The outer orifront end of each bolt 15 be providedwith a squarejhead to reoeiye transversely .therethrough a pivot :pin 21 which carries. the iorliecl of a'bell cranlg I lever 22m The two torlgsof this leyer eirtend toward the plate 13 iorengage nent with an.

inclined. face 23' tlierei pon; and impart-to this plate a variable presfsur e depending upon the angular position of the lever n relation thereto. I The end of the l-ever opposite its,

rorks may be 'rounded as at 25 for 5100,58 engagement within a groove ,26 which -is? formed in a collar 27 having. keyed and; slidable mounting. on the v hub A'secondi,

groove 28 in thiscoliar is adapted to remitte loosely a pair oi studs'29 projecting inwardly vfrom the forked end of an operating'leyer .30

having a pivotal mounting 'as at 31, By inovement transmittedthrough il'llSlBVGl the {Q longitudinal, position of the collarl gmay .be

shifted whereby to actuate" in unison the several bell crank'levers connected therewith, and in this way the pressure upon the plate 13is varied at will. In operation, when the clutch is released the parts will occupy positions somewhat as indicated inFig. 3. The spring 18 is fully expanded, so that the flange 12 and plate 13' are loose with respect to the friction rings 9. This relationship of the parts is assured also 1 5 by expansion of the spring 20. When the clutch is to be engaged, movement trans mitted simultaneously to the levers 22 will cause the bolts 15 to be longitudinally shifted to the position of Fig. 2. In undergoing this movement the springs 18 create a soft engagement due to vthe fact that their coils must be compressed solid before movement of the bolts with respect to the flange 12can be stopped. From this point on, there is no further slipping between these b lts and the flange. It will be noted that equal pressures are applied both to the flange 12 and plate 13 from opposite ends of the bolt, and that these two parts are pressed-against the friction rings 9 so as to receive a driving torque from the common driving member 8. While the clutch parts are undergoing a change 1n position, a flexible engaging period isa'ssured by reason of the expansion or contraction of the springs 18, this period being definitely ended when the clutch is fully engaged or released.

Iclaim: .t

1. A clutch having a driving member and a driven unit consisting of two members each engageable with opposite faces of the driving member, bolts loosely connected with the two driven members having a common cam means for shifting their longitudinal positions in unison, a nut. on each bolt, a compression spring between the nut and one memberof the driven unit and adapted to impart a resilent thrust to one driven member, and other spring means tending normally toseparate said driven members,

substantially as described.

2. A clutch in which is comprised a drive ing member having a pair of friction faces, and a driven unit comprising a pair of members one engageable with each friction face ofthe driving member, means slidably connecting the two driven members whereby they may be moved toward and from each other and the driving member, a stop on each of said connecting means, a compression device interposed between the stop and the proximate driven member whereby to exert upon the'latter a resilient thrust, a cam de vice for each of said connecting means, and a common operating connection for each of said cam devices whereby the said connect ing means may be shiftedin unison to move the two members ofthe driven unit'toward orfroin the driving member, substantially as described, 1

3. A clutch in which is combined a driving member having'a pair of friction faces, a. 7

driven unit comprising a pair of members one in engagement with each face of the driving un1t, means loosely connecting the two driven members and provided at one 4. In a clutch, the combination of a driving member having opposite friction faces,

a driven unitprovided with two members one associated with each face of the driving member, means loosely extended through the two members of the driven unit, a stop at one end of'each said means, springs coiled around said means and interposed between the stops and one member of the driven unit, the coils of the springs being parallel when compressed and adapted before compression to transmit a resilient force to the member when the stop is moved in its direction, and means connected with each of said means for producing a shift in their positions whereby a uniform pressure l is applied to the two driven members for engagement with opposite faces of the driving member, substantially described.

.5. In a clutch, the combination of a two faced driving member and a driven unit having two members one engageable with each face of the driving member, spring means tending normally to release the driven members from engagement with the 7 driving member, and other means connecting the two driven members loosely with each other and including a-stop, a'spring between the stop and one driven member,

and a cam device bearing against the other driven member and adapted to shift the connecting means endwise whereby a Vres'ili ont force is transmitted from the stop, substantially as described. a

ERNEST O. PFAFFE 

